Note: The activities below are demonstrated using material from WHAT MAKES YOU WHAT YOU ARE, which provides a rich introduction to genetics and is highly accessible for students with limited backgrounds.
Activities 1-3 may be used in conjunction with any of the suggested texts on cell biology listed in the materials section ("THE MICROVERSE" (advanced - 10+ - level), "Traits and Fates" (advanced - 10+ - level) or WHAT MAKES YOU WHAT YOU ARE (8th grade level), depending upon students' reading levels and background knowledge.

Preparation: Enlarge and photocopy the diagrams of plant and animal cells provided on page 22 of WHAT MAKES YOU WHAT YOU ARE. Cut out the different internal structural elements of the cells (i.e., nucleus and chromatin, tubes and ribosomes, mitochondria, sacs) and white out the labels provided on page 22, so that each of the cell membranes are now emptied of their internal elements, but are themselves labeled either "plant" or "animal". Place each cell membrane "frame" and cutouts of the structural elements which comprise each cell in manila envelopes. Mix up the structural elements from plant and animal cells. Prepare enough envelopes so that there is one for each group of four or five students.

Steps:

Ask students, "What do you know about cells?" Students may have trouble getting started, and may need "prompt questions" such as "Are cells involved in any diseases you know about?," "Who has cells?," and "Where are cells located?"

Write students' initial responses on the board.

Divide students into groups and have them make a chart with these headings: What do you know about cells? What do you think you know about cells? What more do you want to learn about cells? How can you find these things out?

Ask students to list at least four items under each of the headings.

Reconvene as a class and have students share their questions and prior knowledge.

Distribute envelopes with plant and animal cell membrane "frames" and cutouts of the elements which comprise plant and animal cells. Have students predict which elements belong in both plant and animal cells, and which only belong in one of the two. Have them place all of the cutout elements in the frames, based on their predictions.

Ask students to silently read Chapters 1 and 2 (chapters related to the composition of cells).

When students have finished reading, have them work in their groups once more. Ask them to look again at the puzzles and to make any revisions to their predictions that are necessary.

Have them review their chart and A) make revisions, if necessary, in the columns headed "What do you know about cells?" and "What do you think you know about cells?" and B) If applicable, provide answers to some of the questions they have written under the heading "What do you want to know about cells?"

Reconvene as a class and have students report back their findings.

Activity 2: Spotlight on Mitosis

Steps:

Write the words: growth, repair, and reproduction on the board.

Divide the class into groups of four or five. Distribute newsprint and have each group write an hypothesis about how cells accomplish these three functions. Ask them to include in their hypothesis whether cells accomplish each function through similar or different means.

Reconvene and have groups share their hypotheses and brainstorm ways that they could test their hypotheses: What would they have to observe in order to understand the processes involved in growth, repair, and reproduction? How would they observe them? What materials would they need to observe them? List students' responses on the board.

Ask students to silently read chapters on cell division related to growth and repair (Chapter 3 in WHAT MAKES YOU WHAT YOU ARE).

When students have finished reading, have them correct or augment their hypotheses based on what they have read.

Reconvene as a class and ask groups to report back. Elicit from students A) the name of the process of cell division involved in growth and repair (mitosis) and B) whether it is the same process that is involved in reproduction.

Divide the class into two groups. Using the diagram of the process of mitosis (p. 31 in WHAT MAKES YOU WHAT YOU ARE), have students A) choose a Director and B) perform a role-play demonstrating the process of mitosis, using the captions underneath each frame of the diagram as a guideline for their acting. As students work in groups, circulate to make sure they have included the entire "cast of characters" and suggest to them ways of effectively demonstrating the roles of each "player" (i.e., cell membrane, chromosomes, nucleus, etc.).

Reconvene and ask each group to perform. While each group performs, elicit the steps in the process being performed from the audience. Have them monitor if each of the steps has been explicitly demonstrated.

Activity 3: Introducing Meiosis

Preparation: Reproduce copies of a diagram depicting meiosis, unlabeled (p. 49 in WHAT MAKES YOU WHAT YOU ARE). Prepare a handout of the diagram for each student.

Steps:

Ask students to make a rudimentary drawing of themselves, and to label different features (eyes, nose, mouth, hair color, hair type, height, and weight) with the name of the person from whom they inherited the feature.

Have students share their information in pairs or groups and to note whether there were any features which didn't seem to be inherited from anyone in their family. Ask groups to write an hypothesis explaining the reason for this phenomenon.

Reconvene as a class and have students share hypotheses. Have them look at their drawings again and put a check near the features which may have been affected by environment as well as by heredity. Ask students to then brainstorm responses to the question "What are the steps involved in heredity?" List their responses and, when students have finished responding, have them sequence the steps they came up with.

Divide the class into small groups. Distribute handouts of the meiosis diagram. Tell them it is a diagram of Step One in the process of genetic inheritance. Have them try to write captions describing what they think is going on in each frame of the diagram.

Ask students to read silently Chapters 4 and 5 in WHAT MAKES YOU WHAT YOU ARE (about meiosis and identifying dominant and recessive traits).

Have them work in groups to revise the hypotheses they wrote in Step 2, and to revise/augment the captions they wrote in Step 4.

Reconvene as a class and have groups report back their findings.

Activity 4: Introducing DNA

Prepare copies of the following true/false handout on DNA for each member of the class:

Handout

DNA Fact or Fiction?

Man is the highest of the animals; therefore, he has the most chromosomes.

An injury suffered in an accident will be passed on to one's children.

If your parents both have brown eyes, you will certainly have brown eyes.

You have inherited traits which are not apparent.

Hereditary traits are carried from parent to child through the blood.

Each person inherits half of his genetic makeup from each parent.

You inherit more from your mother if you are a girl.

A parent may give a trait to his child without ever having the trait himself.

If you resemble one parent more than the other, you probably inherited more from that parent.

You have all the hereditary traits you are ever going to have at birth.

Distribute "DNA: Fact or Fiction?" handout and have students work in pairs to complete it.

Ask students to review Chapter 5 and to read Chapter 6 silently.

When students have finished reading, review the "Fact or Fiction" handout with the entire class. Draw attention to the places in the text where the answers to each item are found. Elicit answers and reasons behind the answers from the class.

Direct students to the diagram of a DNA molecule provided in the text (p. 76 in WHAT MAKES YOU WHAT YOU ARE) and the passage describing the different components of the molecule (p. 75 in WHAT MAKES YOU WHAT YOU ARE). Have students work in pairs to identify these components: the "handrail"; the "stairs"; the bases. Have them bracket what they think might be considered a gene, based on the description in the text.

Reconvene and have groups report back their findings.

Activity 5:
DNA Research Put to Use: DNA Sampling

Write on the board two short passages, one from each of the articles, demonstrating the point of view conveyed in the article, such as:

"New York State will embark on one of the nation's most aggressive programs of collecting DNA samples from convicted felons, building a computer database that police can use to solve crimes, under an agreement reached late Thursday night by Gov. George E. Pataki and legislative leaders. Civil libertarians content that DNA samples could eventually be used to extract personal information, such as susceptibility to disease, that could wind up on private hands and violate individuals' rights to privacy;"

and

"One way or another Vincent Jenkins will be freed from the Green Haven correctional Facility in upstate Dutchess County, where he has served nearly 17 years of a life sentence for a rape he didn't commit. DNA tests have ruled out Mr. Jenkins as the man who attacked and raped a woman in a nature preserve in Buffalo in 1982."

Ask students to read each of the passages silently. Review the basic information related to DNA sampling with the class based on their reading.

Ask students to work in pairs to come up with two reasons why DNA sampling might be useful, and two reasons why it could be harmful. Have each pair write a paragraph that either agrees or disagrees with DNA sampling. Paragraphs should include the reasons that suppport their point of view.

Distribute copies of the article "How Many Innocent Prisoners?" to half of the class, and "New York Plan Widely Expands the Sampling of Criminals' DNA" to the other half. Have students read the article while looking for additional reasons why DNA sampling is either harmful or beneficial.

When students have finished reading, have them discuss what they found to be harmful or beneficial in small groups.

Reconvene as a class and have groups report back their findings.

As groups report back, list the reasons why DNA sampling is harmful or beneficial on the board under the headings "Harmful" and "Beneficial."

Re-divide the class into pairs as in Step 3, and have them add to their paragraphs using additional examples elicited in Step 7 to their paragrahs.

Distribute the articles that students did not read in class as homework.

Homework:

1. On paper, have students order the components of a cell from smallest to largest and write a description of the functions each component performs.

2. Have students look at three traits from three family members. They should decide which person each trait was inherited from, if possible, and if it is an example of a dominant or recessive trait.

3. Write an essay on DNA sampling and argue for or against it from one of the following points of view:

a convicted felon who has been found guilty of a crime he did not commit;

a civil rights activist

a police detective.

Research cloning. Collect and read five articles in support of cloning, and five articles that are against cloning. Use the articles to develop an argument essay which relies on facts provided in at least three of the articles.